插入数据到sqlite（第二个表与外键）

Question

我在使用sqlite插入数据时遇到一些困难。该应用程序是测验应用程序，用户需要先输入用户名（不带密码），然后可以在稍后查看分数。测验用户必须先创建用户名（如果是新用户），然后选择用户名（所有用户名将被列出），那么用户需要单击相关的用户名。用户名（almag表）可以成功插入，但不能用于分数表。两个表与用户标识的外键链接。当用户完成测验并按下某个按钮（菜单按钮）时，我希望得分会自动保存，但我仍然面临困难。我希望有人能够提供帮助。

这些是应用程序的一些代码。

数据库中的Java文件

public class DatabaseUsername extends SQLiteOpenHelper { 
private static final String DATABASE_NAME="use.db"; 
private static final int SCHEMA_VERSION=1; 
private View _id; 
public DatabaseUsername(Context context) { 
    super(context, DATABASE_NAME, null, SCHEMA_VERSION); 
} 
@Override 
public void onCreate(SQLiteDatabase db) { 
    db.execSQL("CREATE TABLE almag (_id INTEGER PRIMARY KEY AUTOINCREMENT, nama TEXT, jekel TEXT);"); 
    db.execSQL("CREATE TABLE score (_id INTEGER PRIMARY KEY AUTOINCREMENT, score INTEGER, userId INTEGER NOT NULL, FOREIGN KEY (userId) REFERENCES almag(_id) ON DELETE CASCADE);"); //create table score 
    db.execSQL("PRAGMA foreign_keys = ON;"); 
} 
@Override 
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
    // no-op, since will not be called until 2nd schema 
    // version exists 
} 
public Cursor getAll() { 
    return(getReadableDatabase().rawQuery("SELECT _id, nama, jekel FROM almag ORDER BY nama",null)); 
} 
public Cursor getById(String id) { 
    String[] args={id}; 
    return(getReadableDatabase().rawQuery("SELECT _id, nama, jekel FROM almag WHERE _ID=?",args)); 
} 
public void insert(String nama, String jekel) { 
    ContentValues cv=new ContentValues(); 
    cv.put("nama", nama); 
    cv.put("jekel", jekel);  
    getWritableDatabase().insert("almag", "nama", cv); 
} 
public void insertScore (int _id, int score) { 
    ContentValues cv=new ContentValues(); 
    cv.put("_id", _id); 
    cv.put("score", score); 
    getWritableDatabase().insert("score", "score", cv); 
} 
public void setUsername(View _id) { 
    this._id = _id; 
} 
public String getNama(Cursor c) { 
    return(c.getString(1)); 
} 
public String getJekel(Cursor c) { 
    return(c.getString(2)); 
} 
} 

TheEndActivity

public class TheEndActivity extends Activity implements OnClickListener { 

DatabaseUsername helper=null; 
private int _id; 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.theendactivitylayout); 
    helper=new DatabaseUsername(this); 
    final SetGame currentGame = ((TheApplication)getApplication()).getCurrentGame(); 
    String result = "Your Score is " + currentGame.getRight() + "/" + currentGame.getNumRounds() + ".. "; 
    String comment = Mark.getResultComment(currentGame.getRight(), currentGame.getNumRounds(), getDifficultySettings());  

    TextView results = (TextView)findViewById(R.id.endgameResult); 
    results.setText(result + comment); 

    int image = Mark.getResultImage(currentGame.getRight(), currentGame.getNumRounds(), getDifficultySettings()); 
    ImageView resultImage = (ImageView)findViewById(R.id.resultPage); 
    resultImage.setImageResource(image); 

    Button finishBtn = (Button) findViewById(R.id.finishBtn); 
    Button answerBtn = (Button) findViewById(R.id.answerBtn); 
    finishBtn.setOnClickListener(new View.OnClickListener() { 

    @Override 
    public void onClick(View v) {  
      Intent i = new Intent(TheEndActivity.this, QuizAppActivity.class); 
      startActivity(i); 
      helper.insertScore(_id, currentGame.getRight()); 
    } 
    }); 

    answerBtn.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 

       Intent i = new Intent(TheEndActivity.this, AnsActivity.class); 
       startActivityForResult(i, AppRule.PLAYBUTTON); 
     } 
     }); 

} 

private int getDifficultySettings() { 
    SharedPreferences settings = getSharedPreferences(AppRule.SETTINGS, 0); 
    int diff = settings.getInt(AppRule.DIFFICULTY, 2); 
    return diff; 
} 


    public boolean onKeyDown(int keyCode, KeyEvent event) 
{ 
    switch (keyCode) 
    { 
    case KeyEvent.KEYCODE_BACK : 
     return true; 
    } 

    return super.onKeyDown(keyCode, event); 
} 


    @Override 
    public void onClick(View arg0) { 
     // TODO Auto-generated method stub 

    }} 

UsernameList

public class UsernameList extends ListActivity { 
public final static String ID_EXTRA="com.rika.fyp.player"; 
Cursor model=null; 
AlmagAdapter adapter=null; 
EditText nama=null; 
RadioGroup jekel=null; 
DatabaseUsername helper=null; 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.usernamelist); 

    helper=new DatabaseUsername(this); 

    nama=(EditText)findViewById(R.id.nama); 
    jekel=(RadioGroup)findViewById(R.id.jekel); 
    model=helper.getAll(); 
    startManagingCursor(model); 
    adapter=new AlmagAdapter(model); 
    setListAdapter(adapter); 
} 

@Override 
public void onDestroy() { 
    super.onDestroy(); 

    helper.close(); 
} 

@Override 
public void onListItemClick(ListView list, View view,int position, long id) { 

    helper.setUsername(nama); 
    Intent i=new Intent(UsernameList.this, QuizAppActivity.class); 

    i.putExtra(ID_EXTRA, String.valueOf(id)); 
    startActivity(i); 
}  

@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    new MenuInflater(this).inflate(R.menu.option, menu); 

    return(super.onCreateOptionsMenu(menu)); 
} 

@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    if (item.getItemId()==R.id.add) { 
     startActivity(new Intent(UsernameList.this, UsernameRegister.class)); 

     return(true); 
    } 

    return(super.onOptionsItemSelected(item)); 
} 

private View.OnClickListener onSave=new View.OnClickListener() { 
    public void onClick(View v) { 
     String type=null; 

     switch (jekel.getCheckedRadioButtonId()) { 
      case R.id.pria: 
       type="Pria"; 
       break; 
      case R.id.perempuan: 
       type="Perempuan"; 
       break; 

     } 

     helper.insert(nama.getText().toString(), type); 

     model.requery(); 
    } 
}; 

class AlmagAdapter extends CursorAdapter { 
    AlmagAdapter(Cursor c) { 
     super(UsernameList.this, c); 
    } 

    @Override 
    public void bindView(View row, Context ctxt,Cursor c) { 
     AlmagHolder holder=(AlmagHolder)row.getTag(); 
     holder.populateFrom(c, helper); 
    } 

    @Override 
    public View newView(Context ctxt, Cursor c,ViewGroup parent) { 
     LayoutInflater inflater=getLayoutInflater(); 
     View row=inflater.inflate(R.layout.usernamerow, parent, false); 
     AlmagHolder holder=new AlmagHolder(row); 
     row.setTag(holder); 
     return(row); 
    } 
} 

static class AlmagHolder { 
    private TextView nama=null; 
    private TextView alamat=null; 
    private ImageView icon=null; 
    private View row=null; 

    AlmagHolder(View row) { 
     this.row=row; 

     nama=(TextView)row.findViewById(R.id.title); 
     icon=(ImageView)row.findViewById(R.id.icon); 
    } 

    void populateFrom(Cursor c, DatabaseUsername helper) { 
     nama.setText(helper.getNama(c)); 
     if (helper.getJekel(c).equals("Pria")) { 
      icon.setImageResource(R.drawable.pria); 
     } 
     else if (helper.getJekel(c).equals("Perempuan")) { 
      icon.setImageResource(R.drawable.perempuan); 
     } 

    } 
}} 

我在logcat中得到这些

ERROR /数据库（319）：错误插入得分= 20 _id = 0

ERROR /数据库（319）：android.database.sqlite.SQLiteConstraintException：错误代码19：约束失败

Answer 1

你onCreate()方法看起来过于复杂。试试这个：

public void onCreate(SQLiteDatabase db) { 
    db.execSQL("CREATE TABLE almag (_id INTEGER PRIMARY KEY AUTOINCREMENT, nama TEXT, jekel TEXT);"); 
    db.execSQL("CREATE TABLE score (_id INTEGER PRIMARY KEY AUTOINCREMENT, score INTEGER, userId FOREIGN KEY REFERENCES almag(_id) ON DELETE CASCADE);"); //create table score 
} 

我不能保证它能解决你的问题，但简单有一种清理方法。

也可以尝试改变你的插入方法是：

public void insert(String nama, String jekel) { 
    ContentValues cv=new ContentValues(); 
    cv.put("nama", nama); 
    cv.put("jekel", jekel);  
    getWritableDatabase().insert("almag", null, cv); 
} 

public void insertScore (int _id, int score) { 
    ContentValues cv=new ContentValues(); 
    cv.put("_id", _id); 
    cv.put("score", score); 
    getWritableDatabase().insert("score", null, cv); 
}